On 13/01/10 8:53 PM, Andrus Adamchik wrote:
That is, you might combine expressions with:
exp1.and(exp2, Expression.SPLIT_PATH)
exp1.and(exp2, Expression.MERGE_PATH)
exp1.and(exp2)
I don't understand how the second argument is applicable in the context
of "and"? Anyways,
Split paths can already be added to the Path with "|" in some circumstances.
They can be added to the Expression with matchAll(). And in this case, they are deeply
relevant to the AND because that's what the developer cares about. Do they get zero
results when searching across a many join (which you always do with ANDed expressions and
no split path)? Merging the path is never useful when you are ANDing two expressions.
Thinking about
it, it may be helpful to allow attaching aliases to path expressions
after the fact in Cayenne. I.e. define aliases during the query assembly
stage. Something to think about for 3.1.
It seems that aliases (used in this way) are merely a workaround to the fact
that Expressions need to know whether they should have their paths combined or
not.
Actually I think I see what you mean here. Unfortunately this will only
work for joining simple key/value expression, but won't work when
joining more complex expressions that have more than one key/value pair.
It is not immediately obvious to me why not. I guess I tend to think of Path ==
Expression, since I always always create expressions using matchExp() and
friends. But what happens now if you AND an expression created with matchAll
with another expression with an overlapping path?
Ari
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Aristedes Maniatis
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